Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Hi my name is ***** ***** welcome to just answer. Is this the type carburetor your lawnboy has ? , if so this will tell you exactly where the Jets are at . Also has the carbon ever been cleaned out and pushed into the muffler ?
This is one way to do it ?
The carbon can build up blocking the exhaust ports
At this point I don't believe that you have a carburetor problem, after all it is a very simple design and if you have had it apart four times there shouldn't be anything left in it. I would look at crankshaft seals and reed plates at this point. It is sometimes hard to tell if the seals are bad unless they have actually come out of the block, I would look for any leaks around the seals. The reed plate sometimes get wear on it and won't close properly, it could be cracked causing you to not maintain a crankcase seal if or when this happens you will normally get fuel spray back out of the throat of the carburetor and most of the time it is bad enough that it will constantly soak your air filter.